Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual é o número máximo de cargas de caminhão ao norte?
 ###Tabelas: CREATE TABLE history (history_id AUTO_INCREMENT PRIMARY KEY, Year INT, Road Opened VARCHAR, Road Closed VARCHAR, Freight Carried s Tonne INT, Super B Capacity Reached [ citation needed ] VARCHAR, Number of Truck Loads North INT) CREATE TABLE upcoming_fixtures_and_results (upcoming_fixtures_and_results_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Location VARCHAR, Home Team VARCHAR, Away Team VARCHAR) CREATE TABLE highest_and_lowest_scoring_performances (highest_and_lowest_scoring_performances_id AUTO_INCREMENT PRIMARY KEY, Dance VARCHAR, Best dancer VARCHAR, Best score INT, Worst dancer VARCHAR, Worst score INT) CREATE TABLE girls'_basketball_players_and_coaches_of_the_year (girls'_basketball_players_and_coaches_of_the_year_id AUTO_INCREMENT PRIMARY KEY, Year VARCHAR, Player VARCHAR, School VARCHAR, Hometown VARCHAR, College VARCHAR) CREATE TABLE round_18 (round_18_id AUTO_INCREMENT PRIMARY KEY, Home team VARCHAR, Home team score VARCHAR, Away team VARCHAR, Away team score VARCHAR, Ground VARCHAR, Crowd INT, Date VARCHAR, Report VARCHAR)  
SELECT MAX Number of Truck Loads North FROM history